1. Field of the Invention
The present invention relates to heating appliances and, more particularly, to a combined thermostat and power ON switch assembly.
2. Prior Art
Electric toaster ovens which use thermostats are well known in the art as shown in U.S. Pat. Nos. 3,684,860 and 4,189,632. Snap-acting thermostat switches are also known as shown in U.S. Pat. Nos. 2,237,705 and 2,558,219. For heating controls in toaster ovens of the prior art that use electromechanical control systems, after manual actuation to apply alternating current (AC) line power, a bimetal-based device reacts to a combination of energy, ambient temperature, and time until a desired value is reached. At that point, an electrical signal is generated that signals an AC line power-switching device to turn line power off. Through a user selectable control, the desired value can be varied. For heating controls in toaster ovens of the prior art that use electronic control systems, an electronic circuit is substituted for the bimetal based device. Limitations exist with both of these types of systems in that both systems require a separate AC switching function with related cost, size, and increase in potential failure modes. Some versions also require a separate power switch control power or appliance AC line power.
Single set point, manually resettable thermostats are commonly used in thermal carafe thermostats or other coffee makers that stop AC power with the completion of the brew cycle. These can be reset for a new cycle with manual actuation. Thermostat based controls are commonly utilized in toaster ovens, but AC line power is switched on and off with an independent device. Some prior art toasters utilized a bimetal based control that turned power on by setting a spring loaded latch to close a line power switch and then turned power off by mechanically releasing the spring loaded latch thereby opening the switch. Stevens Manufacturing produced and sold a heating plate in the 1960's with a control having a thermostat.